Techniques for Encoding, Decoding and Representing High Dynamic Range Images

ABSTRACT

Techniques for high dynamic range image processing are presented. Base layer data, first checksum parameter, and residual ratio data for a high dynamic range (HDR) image are each received. A second checksum parameter is computed for the base layer data based upon the first SOF after the last APP11 marker segment and includes all following bytes up to and including the EOI marker. The first and second checksum parameters are compared to determine if base layer has been altered.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation application of U.S. patentapplication Ser. No. 15/110,061 filed on Jul. 6, 2016, which claimspriority to International Application No. PCT/US2015/010299 filed Jan.6, 2015, which claims the benefit of priority from U.S. ProvisionalPatent Application No. 61/924,345 filed Jan. 7, 2014, all incorporatedherein by reference.

TECHNOLOGY OF THE INVENTION

The present invention relates generally to high dynamic range digitalimages. The invention relates specifically to methods and apparatus forencoding and decoding high dynamic range images, whether still or movingpictures, and to data structures containing digital high dynamic rangeimages.

BACKGROUND OF THE INVENTION

Human vision is capable of appreciating contrast ratios of up to1:10,000. That is, a person can take in a scene in which some parts ofthe scene are 10,000 times brighter than other parts of the scene andsee details in both the brightest and darkest parts of the scene.Further, human vision can adapt its sensitivity to brighter or darkerscenes over a further 6 orders of magnitude.

Most conventional digital image formats (so-called 24-bit formats) useup to 24 bits to store color and luminance information for each pixel inan image. For example, each of a red, green and blue (RGB) value for apixel may be stored in one byte (8 bits). Such formats are capable ofrepresenting brightness variations over only about two orders ofmagnitude (each byte can store one of 256 possible values). There exista number of standard formats for representing digital images (whichinclude both still and video images). These include JPEG (JointPhotographic Experts Group), MPEG (Motion Picture Experts Group), AVI(Audio Video Interleave), TIFF (Tagged Image File Format), BMP (BitMap), PNG (Portable Network Graphics), GIF (Graphical InterchangeFormat), and others. Such formats may be called “output referredstandards” because they do not attempt to preserve image informationbeyond what can be reproduced by electronic displays of the types mostcommonly available. Until recently, displays such as computer displays,televisions, digital motion picture projectors and the like have beenincapable of accurately reproducing images having contrast ratios betterthan 1:1000 or so.

Display technologies being developed by the assignee, and others, areable to reproduce images having high dynamic range (HDR). Such displayscan reproduce images which more faithfully represent real-world scenesthan conventional displays. There is a need for formats for storing HDRimages for reproduction on these displays and other HDR displays thatwill become available in the future.

A number of formats have been proposed for storing HDR images as digitaldata. These formats all have various disadvantages. A number of theseformats yield prohibitively large image files that can be viewed onlythrough the use of specialized software. Some manufacturers of digitalcameras provide proprietary RAW formats. These formats tend to becamera-specific and to be excessive in terms of data storagerequirements.

There is a need for a convenient framework for storing, exchanging, andreproducing high dynamic range images. There is a particular need forsuch a framework which is backwards compatible with existing imageviewer technology.

BRIEF DESCRIPTION OF DRAWINGS

The present invention is illustrated by way of example, and not by wayof limitation, in the figures of the accompanying drawings and in whichlike reference numerals refer to similar elements and in which:

FIG. 1 illustrates an exemplary decoding process, according to anembodiment of the present invention;

FIG. 2 illustrates exemplary decoding process, according to anotherembodiment of the present invention;

FIG. 3 illustrates exemplary data contained in an APP11 header segment,according to an embodiment of the present invention;

FIGS. 4A-4B illustrate exemplary segments for a residual ratio image;

FIG. 5 illustrates an example hardware platform on which a computer or acomputing device as described herein may be implemented.

DESCRIPTION OF EXAMPLE POSSIBLE EMBODIMENTS

Example possible embodiments, which relate to HDR encoding, decoding,and data structures, are described herein. In the following description,for the purposes of explanation, numerous specific details are set forthin order to provide a thorough understanding of the present invention.It will be apparent, however, that the present invention may bepracticed without these specific details. In other instances, well-knownstructures and devices are not described in exhaustive detail, in orderto avoid unnecessarily occluding, obscuring, or obfuscating the presentinvention. That said, U.S. Pat. No. 8,514,934, entitled “Apparatus andmethods for encoding, decoding, and representing high dynamic rangeimages,” is incorporated by reference herein for all purposes.

According to one embodiment of the present invention, an HDR datastructure is configured to be readable by legacy image viewers. Thelegacy image viewers can read a tone map information and ignore HDRinformation, such as a ratio data (as explained later). In someembodiments, the data structure comprises a JFIF file and the tone mapinformation comprises a JPEG image. In some embodiments, the datastructure comprises a MPEG file and the tone map information comprises aframe of a MPEG video.

Another aspect of the invention provides a data structure forrepresenting a high dynamic range image having an initial dynamic range.The data structure comprises a tone map portion and a high dynamic rangeinformation portion. The tone map portion contains tone map informationrepresenting the image and has a dynamic range less than the initialdynamic range. The high dynamic range information portion containsinformation describing ratios of (luminance) values in the tone mapportion to luminance values of the high dynamic range image.

Residual Ratio Image

One aspect of this invention provides methods for encoding high dynamicrange image data. The methods involve obtaining, or otherwisegenerating, a tone map information corresponding to the high dynamicrange image data. The tone map information has a dynamic range lowerthan that of the high dynamic range image data. The method computesratio data comprising ratios of values in the high dynamic range imagedata and corresponding values in the tone map information. The ratiodata (or derivative information therefrom) and the tone map informationcan be stored and transmitted for decoding.

Another aspect of this invention provides methods for decoding acodestream to reconstruct a high dynamic range image. The methodsinvolve receiving, or otherwise accessing, a tone map information andcorresponding ratio data (or derivative information therefrom). Themethod computes a high dynamic range image utilizing the values in thetone map information and corresponding ratio data.

Ratio data, as referred to in this application in its entirety, can becomputed, without limitation, (i) as mathematical division of numeratorand denominator values, including without limitation, furthermathematical operations—such as logarithm of the ratio, or (ii)alternatively, as subtraction of two logarithmic values, includingwithout limitation, further mathematical operations. Typically, ratiodata describes luminance, but can be used for chroma channels (e.g., Cr,Cb) as well. For the sake of clarity, ratio data is sometimes describedherein as residual data or included with residual data.

FIG. 1 illustrates an exemplary decoding process according to anembodiment of the present invention. The process begins with a legacydecoder block which reconstructs the base image. This image is thenoptionally chroma upsampled, followed by an inverse decorrelation block.The output of this transformation is a low-dynamic range, backwardcompatible image with eight bits per sample in, for example, an RGB-typecolor space.

The low-dynamic range components are further mapped by the base mappingand color space conversion block to a floating point image which iscalled a precursor image. The precursor image is optionally converted toHDR color space and luminance can be calculated. The noise level maybeused to avoid division by zero and to reduce the compression artifactswhich can be amplified in following blocks.

The residual decoder path uses the residual data that is embedded in thecodestream in the APP11 markers. This data is reconstructed and thenoptionally upsampled. It is then processed by a residual mapping andinverse decorrelation block. This block maps the residual data tofloating point domain which is optionally inversely decorrelated. Thismapping can use the luminance computed by the base mapping and colorspace conversion block. The mapped residual data and the precursor imageare processed by the HDR reconstruction block to produce a reconstructedHDR Image.

FIG. 2 illustrates exemplary decoding process according to anotherembodiment of the present invention. The decoding process relies on alayered approach by decomposing an HDR image into a base layer and anHDR residual ratio layer. The base layer is a tone mapped image tonemapped from the original floating point HDR with either a local orglobal tonemapper. This codestream will be the backwards compatiblewith, accessible by, legacy decoders. The residual ratio layer containsHDR quantized log luminance ratio and the chrominance residualdifference, this data is put together and represented as a singleresidual ratio image.

Since the residual data is hidden in the APP11 markers, legacy decoderscan skip over this residual image and only access the base image codesstream, and thus this decoding process is backwards compatible. However,decoders implementing the present invention can combine the two layersto reconstruct an HDR image.

In FIG. 2, the upper path which comprise of blocks B1, B2, and B3 can bethe standard flow of a legacy decoder and outputs a backwards compatiblelower dynamic range (LDR) image in typically sRGB space. This base imagedata is then mapped into linear HDR space and processed by the colorspace conversion operation in block B4. This block converts the LDRimage into the color space of the original HDR image, and it also mapsthe image to floating point value and called linear pre RGB2, it canalso be referred to as “LP_RGB2.” A noise floor value specified in theparameter codestream is added to the luminance component of the LP_RGB2to avoid divide by 0 and to avoid amplifying any noise that could occurdue to operations downstream from this block B4 for small values.

In FIG. 2, the lower path starting from B5 begins with the residual dataof the high-dynamic range image, and is represented by the ISO/IEC10918-1 codestream format (which is incorporated by reference for allpurposes, and to show desired formats). This codestream is embedded inthe APP11 marker as a residual data segment described below. After beingdecoded by the decoder the chroma upsampling step is performed by B6 tobring all components to full resolution, e.g., 4:4:4.

The residual ratio data is then separated by B7 into floating pointlinear ratio luminance values and a linear residual color differencevalue. The incoming residual luminance values are inverse quantizedaccording to parameters in the codestream. A specific embodiment, thisis either provided by an explicit lookup table in the parameter segmentin the codestream. If this table is not present, then using the min andmax, referred to as ln1, ln0 in the parameters segment, and an inverselog map is calculated. Similarly, the incoming chroma residual samplevalues are inverse quantized according to the minimum and maximumparameters stored in the parameter segment of the codestream as cb0, cb1and cr0, cr1, if present.

The chroma values are then processed by B8, the YCbCr to RGB2 block andwill convert the linear dequantized YCbCr to a linear residue RGB2 inthe HDR color space, alternatively referred to as “LR_RGB2.” Finally,blocks B9 and B10 constructs an HDR image by first adding the linear preRGB2 to the linear residue RGB2 in B9 and then multiplying the result bythe linear ratio luminance in B10.

APP11 Marker

As shown in FIG. 3, the APP11 marker segment is broken into a parameterdata segment and a data segment. The parameter segment has two or more(e.g., 3) types of segments, such as a parameter ASCII type segment,residual segment, and a parameter binary type segment. This structurefor the APP11 marker segment can be used in connection with anyembodiment of the invention described herein, including withoutlimitation, the exemplary embodiments reflected in FIGS. 1 and 2.

Checksum for Edit Detection

A parameter data segment (PDS) carries parameters encoded, as ASCII orbinary text, as payload data. The last parameter in the segment is achecksum of the base layer codestream. In a specific embodiment, the ckb(ASCII) or chksum (binary, 16 bits) parameter is a checksum of the baselayer codestream computed by summing all bytes in the base layercodestream. The checksum includes the first SOF (e.g., start of frame)marker after the last APP11 marker segment and includes all followingbytes up to and including the EOI (e.g., end of frame) marker. It can beused by the decoder to detect an edit of the base layer, which mayresult in undesirable artifacts when the high dynamic range (HDR) imageis decoded. In a specific embodiment, the checksum is position (ororder) dependent, such as a Fletcher's checksum (e.g., Fletcher-16,Fletcher-32, Fletcher-64). See Fletcher, J. G. (January 1982). “AnArithmetic Checksum for Serial Transmissions,” IEEE Transactions onCommunications, COM-30 (1): 247-252 for additional information, which isincorporated herein by reference for all purposes.

In an alternative embodiment, the PDS can indicate the use of a morecomplex hash algorithm than checksum. A more complex hash algorithmreduces the possibilities of hash collisions, e.g., undetectablealterations in the data when different input data results in same hashvalue. According, a hash value generated for the original base layershould probabilistically be unlikely to match if the base layer isaltered. Exemplary hash functions can be, or implemented by:

-   -   (i) nonlinear lookup table;    -   (ii) cryptographic hash function (e.g., HAIFA, Merkle-Damgård,        unique block interation, and the like);    -   (iii) non-cryptographic hash function (xor, product, addition,        rotation);    -   (iv) randomized that selects a hashing function among a        predefined set;    -   (v) cyclic redundancy check(s); and    -   (vi) checksum(s)—e.g., Fletcher, Adler-32.

In yet other alternative embodiments, fingerprinting or mediawatermarking techniques can be signaled by the PDS and verified duringdecoding or image reproduction/rendering.

The checksum, hash function or the other described alternatives for baselayer edit detection can be used in connection with any embodiment ofthe invention described herein, including without limitation, theexemplary embodiments reflected in FIGS. 1 and 2. Additionally, based onthe teaching herein, a checksum, hash function or alternative can beused for edit detection of the residual ratio layer too.

Encryption/Decryption of the Residue Layer Implemented on a Per SegmentBasis

Another parameter within the PDS or elsewhere can be an encryptionparameter, such as an encryption key. This information can be used todecrypt the ratio residue layer, for example, on a per segment basis ofthe codestream. A segment can be an independently decodable sequence ofentropy encoded bytes of compressed image data. In other words,according to an embodiment of the present invention, a differentencryption parameter can be provided and used for each segment. Theencryption parameter and associated processing can be used in connectionwith any embodiment of the invention described herein, including withoutlimitation, the exemplary embodiments reflected in FIGS. 1 and 2.

Inverse Tone Mapping in the Degamma Lut/Mapping Lut

A degamma lookup table (LUT) described above (as block B4 in FIG. 2) isa 256 entry table loaded by a default Rec. 601 table (ITU-RRecommendation BT.601, available athttp://www.itu.int/rec/R-REC-BT.601-7-201103-I/en, which is incorporatedby reference) which is typically an inverse linear and power function of2.4. If it is in an alternate color space, such as Adobe RGB by AdobeSystems, Inc., the look up table can be sent in header information.Additionally, the degamma LUT can include an inverse tone mappingfunction/curve, such as for reverse histogram equalization or inverseReinhard tone mapper. In some cases, the degamma LUT with inverse tonemapping can reduce memory used for the residual ratio layer. Foradditional information on the Reinhard tone mapper, seehttp://www.cs.utah.edu/˜reinhard/cdrom/tonemap.pdf (“Photographic ToneReproduction for Digital Images”), which is incorporated by referenceherein for all purposes.

Binary Header Segment

The APP11 marker segment can include binary parameter data, as shown as“Type 3” in FIG. 3. The Type 3 segment and its associated processing canbe used in connection with any embodiment of the invention describedherein, including without limitation, the exemplary embodimentsreflected in FIGS. 1 and 2.

Segment Index and Start Location for That Segment

In an embodiment of the present invention, the span and extent ofsegments for residual ratio image need to be coincident with a baselayer image. For example, a residual ratio image can be partitioned intoa plurality of segments, contiguous and non-contiguous. A set of thesesegments of the residual ratio image need not correspond to a completeimage, but can define one or more portions of an image. Thisfunctionality allows HDR reconstruction from a portion of the base layerimage, but not the entire base layer image. For example, an encryptionparameter can be provided for one segment (e.g., left half image, tophalf image) for HDR reconstruction, while residual ratio information foranother segment (e.g., right half image, bottom half image) remainsencrypted for limited base layer reproduction.

Each segment of the residual ratio image can be specified by coordinatereferences (e.g., x and y coordinates for one of the four corners ifrectangular segment) and its length and width. If segment is a differentgeometric shape, then it can be defined by a center position and aradius/diameter or the like. FIGS. 4A-4B illustrate exemplary segmentsof the residual ratio image, which can used in connection with anyembodiment of the present invention, including without limitation, theexemplary embodiments reflected in FIGS. 1 and 2.

Implementation Mechanisms—Hardware Overview

According to one embodiment, the techniques described herein areimplemented by one or more special-purpose computing devices. Thespecial-purpose computing devices may be hard-wired to perform thetechniques, or may include digital electronic devices such as one ormore application-specific integrated circuits (ASICs) or fieldprogrammable gate arrays (FPGAs) that are persistently programmed toperform the techniques, or may include one or more general purposehardware processors programmed to perform the techniques pursuant toprogram instructions in firmware, memory, other storage, or acombination. Such special-purpose computing devices may also combinecustom hard-wired logic, ASICs, or FPGAs with custom programming toaccomplish the techniques. The special-purpose computing devices may bedesktop computer systems, portable computer systems, handheld devices,networking devices or any other device that incorporates hard-wiredand/or program logic to implement the techniques.

For example, FIG. 5 is a block diagram that illustrates a computersystem 1600 upon which an embodiment of the invention may beimplemented. Computer system 1600 includes a bus 1602 or othercommunication mechanism for communicating information, and a hardwareprocessor 1604 coupled with bus 1602 for processing information.Hardware processor 1604 may be, for example, a general purposemicroprocessor.

Computer system 1600 also includes a main memory 1606, such as a randomaccess memory (RAM) or other dynamic storage device, coupled to bus 1602for storing information and instructions to be executed by processor1604. Main memory 1606 also may be used for storing temporary variablesor other intermediate information during execution of instructions to beexecuted by processor 1604. Such instructions, when stored innon-transitory storage media accessible to processor 1604, rendercomputer system 1600 into a special-purpose machine that is customizedto perform the operations specified in the instructions.

Computer system 1600 further includes a read only memory (ROM) 1608 orother static storage device coupled to bus 1602 for storing staticinformation and instructions for processor 1604. A storage device 1610,such as a magnetic disk or optical disk, is provided and coupled to bus1602 for storing information and instructions.

Computer system 1600 may be coupled via bus 1602 to a display 1612, suchas a liquid crystal display, for displaying information to a computeruser. An input device 1614, including alphanumeric and other keys, iscoupled to bus 1602 for communicating information and command selectionsto processor 1604. Another type of user input device is cursor control1616, such as a mouse, a trackball, or cursor direction keys forcommunicating direction information and command selections to processor1604 and for controlling cursor movement on display 1612. This inputdevice typically has two degrees of freedom in two axes, a first axis(e.g., x) and a second axis (e.g., y), that allows the device to specifypositions in a plane.

Computer system 1600 may implement the techniques described herein usingcustomized hard-wired logic, one or more ASICs or FPGAs, firmware and/orprogram logic which in combination with the computer system causes orprograms computer system 1600 to be a special-purpose machine. Accordingto one embodiment, the techniques as described herein are performed bycomputer system 1600 in response to processor 1604 executing one or moresequences of one or more instructions contained in main memory 1606.Such instructions may be read into main memory 1606 from another storagemedium, such as storage device 1610. Execution of the sequences ofinstructions contained in main memory 1606 causes processor 1604 toperform the process steps described herein. In alternative embodiments,hard-wired circuitry may be used in place of or in combination withsoftware instructions.

The term “storage media” as used herein refers to any non-transitorymedia that store data and/or instructions that cause a machine tooperation in a specific fashion. Such storage media may comprisenon-volatile media and/or volatile media. Non-volatile media includes,for example, optical or magnetic disks, such as storage device 1610.Volatile media includes dynamic memory, such as main memory 1606. Commonforms of storage media include, for example, a floppy disk, a flexibledisk, hard disk, solid state drive, magnetic tape, or any other magneticdata storage medium, a CD-ROM, any other optical data storage medium,any physical medium with patterns of holes, a RAM, a PROM, and EPROM, aFLASH-EPROM, NVRAM, any other memory chip or cartridge.

Storage media is distinct from but may be used in conjunction withtransmission media. Transmission media participates in transferringinformation between storage media. For example, transmission mediaincludes coaxial cables, copper wire and fiber optics, including thewires that comprise bus 1602. Transmission media can also take the formof acoustic or light waves, such as those generated during radio-waveand infra-red data communications.

Various forms of media may be involved in carrying one or more sequencesof one or more instructions to processor 1604 for execution. Forexample, the instructions may initially be carried on a magnetic disk orsolid state drive of a remote computer. The remote computer can load theinstructions into its dynamic memory and send the instructions over atelephone line using a modem. A modem local to computer system 1600 canreceive the data on the telephone line and use an infra-red transmitterto convert the data to an infra-red signal. An infra-red detector canreceive the data carried in the infra-red signal and appropriatecircuitry can place the data on bus 1602. Bus 1602 carries the data tomain memory 1606, from which processor 1604 retrieves and executes theinstructions. The instructions received by main memory 1606 mayoptionally be stored on storage device 1610 either before or afterexecution by processor 1604.

Computer system 1600 also includes a communication interface 1618coupled to bus 1602. Communication interface 1618 provides a two-waydata communication coupling to a network link 1620 that is connected toa local network 1622. For example, communication interface 1618 may bean integrated services digital network (ISDN) card, cable modem,satellite modem, or a modem to provide a data communication connectionto a corresponding type of telephone line. As another example,communication interface 1618 may be a local area network (LAN) card toprovide a data communication connection to a compatible LAN. Wirelesslinks may also be implemented. In any such implementation, communicationinterface 1618 sends and receives electrical, electromagnetic or opticalsignals that carry digital data streams representing various types ofinformation.

Network link 1620 typically provides data communication through one ormore networks to other data devices. For example, network link 1620 mayprovide a connection through local network 1622 to a host computer 1624or to data equipment operated by an Internet Service Provider (ISP)1626. ISP 1626 in turn provides data communication services through theworld wide packet data communication network now commonly referred to asthe “Internet” 1628. Local network 1622 and Internet 1628 both useelectrical, electromagnetic or optical signals that carry digital datastreams. The signals through the various networks and the signals onnetwork link 1620 and through communication interface 1618, which carrythe digital data to and from computer system 1600, are example forms oftransmission media.

Computer system 1600 can send messages and receive data, includingprogram code, through the network(s), network link 1620 andcommunication interface 1618. In the Internet example, a server 1630might transmit a requested code for an application program throughInternet 1628, ISP 1626, local network 1622 and communication interface1618.

The received code may be executed by processor 1604 as it is received,and/or stored in storage device 1610, or other non-volatile storage forlater execution.

Equivalents, Extensions, Alternatives and Miscellaneous

In the foregoing specification, possible embodiments of the inventionhave been described with reference to numerous specific details that mayvary from implementation to implementation. Thus, the sole and exclusiveindicator of what is the invention, and is intended by the applicants tobe the invention, is the set of claims that issue from this application,in the specific form in which such claims issue, including anysubsequent correction. Any definitions expressly set forth herein forterms contained in such claims shall govern the meaning of such terms asused in the claims. Hence, no limitation, element, property, feature,advantage or attribute that is not expressly recited in a claim shouldlimit the scope of such claim in any way. The specification and drawingsare, accordingly, to be regarded in an illustrative rather than arestrictive sense.

ADDITIONAL REFERENCES

The following references, in addition to references cited above, areincorporated by reference herein for all purposes:

(i) ITU-T Rec. T.81 | ISO/IEC 10918-1: Information Technology—DigitalCompression and Coding of Continuous Tone Still Images—Requirements andGuidelines

(ii) ITU-T Rec. T.86 | ISO/IEC 10918-4: Information technology—Digitalcompression and coding of continuous-tone still images: Registration ofJPEG profiles, SPIFF profiles, SPIFF tags, SPIFF colour spaces, APPnmarkers, SPIFF compression types, and Registration Authorities

(iii) ITU-T Rec. T.871 | ISO/IEC 10918-5: Information technology—Digitalcompression and coding of continuous-tone still images: JPEG FileInterchange Format

(iv) ITU-T Rec. T.801 | ISO/IEC 15444-1: Information technology—JPEG2000 Image Coding System; and

(v) IEC 60559 Binary floating-point arithmetic for microprocessorsystems.

What is claimed is:
 1. A method for decoding with edit detection, themethod comprising: receiving base layer data for a high dynamic range(HDR) image, the base layer data accessible by a legacy image viewer;receiving a Type 1 parameter American Standard Code for InformationInterchange (ASCII) segment, as identified by one byte in the Type 1parameter ASCII segment; receiving a Type 2 residual segment, as isidentified by one byte in the Type 2 residual segment, wherein the Type1 parameter ASCII segment further includes a payload having a maximum ofa first size, and the Type 2 residual segment further includes a payloadhaving a maximum of a second size, the first size differing from thesecond size; receiving, in the Type 1 parameter ASCII segment, a firstchecksum parameter for the base layer data, the first checksum parameterto be utilized by an HDR decoder and ignored by the legacy image viewer;receiving, in the Type 2 residual segment, residual ratio data for theHDR image; for the HDR decoder: computing a second checksum parameterfor the base layer data; and comparing the first checksum parameter tothe second checksum parameter; and decoding the HDR image based on thebase layer data, the residual ratio data, and a result of comparing thefirst checksum parameter to the second checksum parameter.
 2. The methodof claim 1 wherein the first size is 64 k less 12 bytes.
 3. The methodof claim 1 wherein the second size is 64 k less 9 bytes.
 4. The methodof claim 1 wherein Type 1 parameter ASCII segment further includes aversion byte following a profile byte.